Tap or not legal

[little george]

Here's the setting: We have a 400a. fused Service switch with double barrel lugs on the load side feeding two 200a. panels containing a 200a. main in each one. The wire supplying the 400a. switch are rated for 400a. and the wires feeding the 200a. panels are rated for 200a. I maintain that all wires are protected at their ampacity and that this is a common installation. This would be comparable to the rules for taps found in 240.21 where conductors are protected at their load ends instead of their source. My learned colleagues say "Can't do that, it ain't a tap" What say you guys?

 

[david]

Here's the setting: We have a 400a. fused Service switch with double barrel lugs on the load side feeding two 200a. panels containing a 200a. main in each one. The wire supplying the 400a. switch are rated for 400a. and the wires feeding the 200a. panels are rated for 200a. I maintain that all wires are protected at their ampacity and that this is a common installation. This would be comparable to the rules for taps found in 240.21 where conductors are protected at their load ends instead of their source. My learned colleagues say "Can't do that, it ain't a tap" What say you guys?

you are taping the load side of the 400 amp fused disconnect. If it can be done in a code compliant way or not would be in the details that you haven't provided

 

[infinity]

Ask this guy "Can't do that, it ain't a tap" where is states that in the code book. Sounds like it complies with either the 10' or 25' tap tule to me.

 

[kwired]

Here's the setting: We have a 400a. fused Service switch with double barrel lugs on the load side feeding two 200a. panels containing a 200a. main in each one. The wire supplying the 400a. switch are rated for 400a. and the wires feeding the 200a. panels are rated for 200a. I maintain that all wires are protected at their ampacity and that this is a common installation. This would be comparable to the rules for taps found in 240.21 where conductors are protected at their load ends instead of their source. My learned colleagues say "Can't do that, it ain't a tap" What say you guys?

If the two 200 amp load conductors were joined together at both ends, you then would have paralleled conductors and the effective result is the same as a single 400 amp conductor. But as is you have two separate 200 amp conductors protected on the supply by more than their ampacity. That is permitted if the applicable "tap rules" are followed. There are three basic situations that would apply, the 10 foot rule, the 25 foot rule, and outdoor taps which are unlimited in length. There is also rules that include transformer secondary conductors that are still somewhat a mixture of the 10 and 25 foot rules but with a transformer involved, and there is also industrial exceptions typically for high ceiling applications where the tap is primarily a vertical run.

 

[qcroanoke]

Here's the setting: We have a 400a. fused Service switch with double barrel lugs on the load side feeding two 200a. panels containing a 200a. main in each one. The wire supplying the 400a. switch are rated for 400a. and the wires feeding the 200a. panels are rated for 200a. I maintain that all wires are protected at their ampacity and that this is a common installation. This would be comparable to the rules for taps found in 240.21 where conductors are protected at their load ends instead of their source. My learned colleagues say "Can't do that, it ain't a tap" What say you guys?

Is to a tap!

 

[mwm1752]

Your protection is in place. How many gutters have been fed by a service riser only to tap to individual mains with appropriate wire sizing? Agree it is a tap.

 

[infinity]

Your protection is in place. How many gutters have been fed by a service riser only to tap to individual mains with appropriate wire sizing? Agree it is a tap.

If they're service entrance conductors do the tap rules apply or are they still SEC's?

 

[kwired]

If they're service entrance conductors do the tap rules apply or are they still SEC's?

They are still service conductors, and there are no tap rules in relation to overcurrent protection for service conductors.

 

[mwm1752]

True the OP statement should be limited to art 240 tap rules as it is a feeder tap. I do apologize my premise was more intended as a visual installation similar to the OP though the conductors were unfused where they are spliced/tapped. Interesting enough 230.46 does refer to the SEC splicing with the term tapped & 230.90 in turn defines conductor sizing to the OC device.

 

[charlie b]

But if the 400 amp "service switch" constitutes the service point (i.e., N-G bond is in that location), would the two 200 amp runs not be "feeders"?

 

[infinity]

But if the 400 amp "service switch" constitutes the service point (i.e., N-G bond is in that location), would the two 200 amp runs not be "feeders"?

Regarding the OP, yes they would be feeders with feeder taps. If they were on the line side of the service switch then no they would not be feeder taps since all of the conductors would be SEC's.

 

[kwired]

True the OP statement should be limited to art 240 tap rules as it is a feeder tap. I do apologize my premise was more intended as a visual installation similar to the OP though the conductors were unfused where they are spliced/tapped. Interesting enough 230.46 does refer to the SEC splicing with the term tapped & 230.90 in turn defines conductor sizing to the OC device.

Many seem to confuse terminology and think the word "tap" only applies to 240.21(B) When the correct terminology that is applied in 240.21(B) is "feeder taps"

There is no art 100 definition for "tap" so there is no specific meaning for that word when used through the rest of the code, just the general definitions found in a dictionary. Using the word feeder with it limits the meaning for that particular usage, and feeder is a code defined word.

 

[mwm1752]

Many seem to confuse terminology and think the word "tap" only applies to 240.21(B) When the correct terminology that is applied in 240.21(B) is "feeder taps"

There is no art 100 definition for "tap" so there is no specific meaning for that word when used through the rest of the code, just the general definitions found in a dictionary. Using the word feeder with it limits the meaning for that particular usage, and feeder is a code defined word.

Gotcha== point being whether a SEC of feeder the conductor tapped/spliced is sized to the OC device protecting it.